fping

fping is a program like ping which uses the Internet Control Message Protocol to determine if a target host is responding. Contrary to it model fping can be use to target any number of targets. Its output is also designed to be easier to parse.

Command examples

To test a simple host:

fping 172.31.0.1
172.31.0.1 is alive

To scan an entire network by sending just one packet by IP:

fping -a -r 0 -g 172.31.0.0/24

You can make the process faster by decreasing the interval between packet with the -i parameter:

fping -a -i 1 -r 0 -g 172.31.0.0/24

To use a list of IP:

fping -a < host_list.txt

Remount a filesystem as read/write

Sometimes due to a failed update or a bad manipulation you may end up with no other choice then reboot your system into ‘recovery mode‘. In this setting the root partition is mounted in read only. To remount it in read/write:

# mount -o remount,rw /